Preparation

• In a medium bowl, whisk together the all-purpose flour, baking soda, and salt until thoroughly combined. Set this mixture aside to use shortly.
• In a large mixing bowl, beat the softened unsalted butter with the light brown and granulated sugars on medium speed until the mixture is visibly paler and fluffy.
• Beat in the large egg and then the egg yolk, one at a time, mixing well after each addition.
• Pour in the vanilla extract and mix until it’s smoothly blended into your dough.
• Gradually add your dry flour mixture to the wet ingredients. Beat on low just until the dough starts coming together.
• Add 1 teaspoon of milk and lightly mix until it’s just absorbed. If the dough seems dry, add another teaspoon of milk.
• Stir in the white chocolate chips and chopped macadamia nuts with a spatula or wooden spoon.
• Scoop out balls of dough, each about 2 tablespoons in size, and place them onto a parchment-lined baking sheet or plate.
• Place the dough balls in the refrigerator for at least 2–3 hours, or overnight for thick, chewy cookies.
• Preheat your oven to 350°F (180°C). Line baking sheets with parchment paper to prevent sticking.
• Arrange the cookie dough balls on your prepared baking sheets, leaving space for spreading. Bake for 8–9 minutes, until the edges start to turn light golden.
• Let cookies cool on the baking sheets for 4–5 minutes to set up. Transfer to a wire rack to cool completely for best texture.